Vehicle window



J. MUTTRAY E! AL VEHICLE WINDOW Filed Dec. 15, 1957 June 4, 1940.

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v Patented June 4, 1940 I I v UNlTE Dl STATES PATENT OFFICE vsnlzfi wlimow I I Justus'Muttray and Wilfried Vogel, Dessau, Germany, assignors toJunkers Flugzeug-und-Mo- .torenwerke Aktiengesellschaft, Des'sau',Germany Application December 15, 1937, Serial No. 179,876 In GermanyDecember 28,1936

4 Claims. (01. go-40.5.)

Our invention relates to windows and more useful in the case where thewindow is connected especially to the windows of vehicles and airwith avehicle. If it forms part of an aircraft, craft. It is an object of ourinventionto provide the stays preferably extend in planes extendingmeans whereby the formation of an ice layer on in the direction oftravel so that any corruga- 5 the outer pane of double windows can beeffitions formed in'consequence of the yielding na- 5 ciently prevented.ture of the outer pane extend in a direction In order to prevent theobstruction of sight such that the formation of whirls in the airflowbrought about by the formation of ice on a wining past the window isavoided. dow pane it has already been suggested to use, in In thedrawing affixed to this specification and connection with motorvehicles, double windows forming part thereof two windows embodying our10 and to pass hot air throughthe space enclosed invention areillustrated diagrammatically by between the outer and inner panes. Insuch way of example. arrangement the outer pane was made sufllciently Inthe drawing thick-walled to be able to take up the forces Fig. l is adouble window which is arranged acting thereon from without and inconsequence in the space delimited by the outer wall of a of therelative thickness of this pane a relatively high-altitude cabin of anaircraft, great amount of heat energy was required to "Fig. 2 being across section on the line II- keep the outer surface ofthe outer paneeven in Fig. 1.

moderately warm, so that it was not possible to Fig. 3 shows a pluralityof double-walled winprevent the formation of ice on the outer. surdowsarranged on the cockpit of an aircraft, 0

face under all circumstances. I v Fig. 4 being across section on theline IV-IV. According tothe presentinvention this drawin Fig. 3, whileback is avoided by providing an inner pane, which Fig.5 shows a part ofFig. 4 drawn to a larger is sufficiently tlnck-walled-to be able to takeup scale. a all mechanical stresses, while the outer pane is Referringto the drawing and first to Figs. '1' 25 relatively thin-walled inproportion. We thereand-2,1 is the inner pane, 2 the outer pane. The byobtain that the outer surface of the outer I inner pane issufficientlythick walled to take up pane is heated up sufficiently witha small amount the stresses and more particularly those acting on ofheat energy, since owing to its thickness a betthe pane in consequenceofthe increased pressure ter transmission of heatis secured. prevailingin the cabin. In contradistinction 30 We have found it particularlyadvantageous to thereto the outer pane 2 is thin-walled similar to usean-outer pane consisting of a thin film of a a film and consists of amaterialresistive against transparent material adapted to resisttentensional forces. The space 3 enclosed between sional strain, whichis'rigidly fixed in spaced rethe two panes is traversed. by a gaseousheating lationsliip to the inner pane at a substantially ,medium actedon by a pressure .which is sub- 36 permanently fixed distance therefrom,i. e. is destantially equal to the pressure prevailing on the formableat most within the limits-of its elasoutside of the pane 2, so that thispane is reticity without being capable of any fartherreachlieved of allstrains in a far reaching manner. ing, predetermined deformation. Theheating In the modification illustrated in Figs. 3 to 5 40 mediumflowing through the interstice between the inner panes I are alsothick-walled, while 40 the outerand inner panesis then acted upon by theouter panes 2 are thin-walled, being made of a pressure which issubstantially equal to the a material resistive against tensionalforces. pressure acting on the outer surface of the outer Owing to thethinness of the outer pane 2 the pane. The heating medium thus servesfor takresistance it opposes to the transmission of heat ing up theforces acting from without on the from its inner to its outer surface islow. Even 45 outer pane, so, that this pane is greatly relieved withgreat differences between the temperatures of any loads acting thereonand .can therefore of the space enclosed between the panes and the be,made particularly thin and therefore also outer air the outer pane thusundergoes only a highly heat conductive. In order to furtherrecomparatively small drop of temperature and lieve the outer pane, weprefer to connect it therefore the temperature of the outer pane can 5with preferably transparent stays, which are easily be keptabove'freezing point even at low preferably supported by the inner paneand hold temperatures, so that the formation of ice on 'the the outer'pane uniformly spaced from'the inouter pane is avoided. Moreover owingto the ner pane in order to prevent fluttering of the outer pane beingkept warm by the heating medi-' outer pane. This arrangement isparticularly um, the properties of the material remain almost vl5unchanged even if the outer temperature varies within wide limits, Aparttherefrom, the weight of these panes is very low.

In order to prevent the outer panes 2 from moving (fluttering) under theinfluence of the travelling wind, these panes are connected with stays 4(Fig. 2) secured to the inner pane I. These stays 4 are located inplanes extending in the direction of flight and consequently also suchcorrugations which may form owing to the yielding nature of the outerpanes 2 will extend in the same direction.

In the modification illustrated in Figs. 3 to 5 no such stays areprovided, since the individual panes are comparatively small.

As shown in Figs. 2 and 5 the outer and inner panes are mounted in placein such manner that the edges of the panes I and 2 are formed withbulged portions 5, which are held in settings 1 formed on the frames, ayielding layer 6 being inserted between the bulging edges of the panesand their seats in the frame.

The gaseous heating medium. is supplied to and exhausted from theinterstice 3 by means of pipes 8 and 9, respectively, means such asperforations H and I2 being provided in the stays 4 (Figs. 1 and 2) andin the stays l0 (Figs. 3 and 4) respectively, which are arranged instaggered relation, whereby the panes I and 2 are uniformly contactedall over their surface by the heating medium.

Various changes may be made in the details disclosed in the foregoingspecification without departing from the invention or sacrificing theadvantages thereof.

We claim:

1. In an aircraft, a double-walled defrosting window subject toexcessivewind pressure from outside and comprising a relatively thick inner pane,a relatively thin. but substantially rigid outer pane in spaced relationthereto, means substantially sealing the space between said panes, andcontrollable means for building up within said space avariabletemperature and uniform pressure adapted to simultaneously inhibit theformation of frost on the outside of the outer pane and substantiallycounterbalance excess pressure exerted thereon from without.

2. In an aircraft, a double-walled defrosting window subject toexcessive wind pressure from outside and comprising a relatively thickinner pane, a relatively thin but substantially rigid outer pane inspaced relation thereto, means substantially sealing the space betweensaid panes, and means for introducing into the space a heated gaseousmedium under uniform pressure sufficient to counterbalance the excessair pressure exerted on the outside of the outer pane to thereby preventflexing of the same to the point of breakage.

3. In an aircraft, a double-walled defrosting window subject toexcessive wind pressure from outsideand comprising a relatively thickinner pane, a' relatively thin but substantially rigid outer pane inspaced relation thereto, means substantially sealing the space betweensaid panes, and means for introducing into the space a heated gaseousmedium under uniform pressure sufficient to counterbalance the excessair pressure exerted on the outside of the outer pane to thereby preventflexing of the-same to the point of breakage, said means including inletand outlet conduits into the space between the panes.

4. That method of preventing the formation of frost on the outer surfaceof an aircraft window subject to excessive wind pressure from theoutside which consists in formingthe outer pane of a sealeddouble-walled window of relatively thin but substantially rigidtransparent substancecapable of rapidly absorbing heat and introducinginto the space between the inner and outer panes a heated gaseoussubstance under uniform pressure suilicient to counterbalance the excessair pressure exerted on the outside of the outer pane to thereby preventflexing of the latter to the point of breakage. v

' JUSTUS MU'I'IRAY. WILE- RIED VOGEL.

